---
title: "FallbackSTT | Micdrop"
description: "The FallbackSTT class provides automatic failover between multiple STT providers for improved reliability."
url: "https://micdrop.dev/docs/ai-integration/fallback-strategies/stt-fallback"
---

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[Micdrop](/) › [Documentation](/docs/getting-started)

# FallbackSTT

The `FallbackSTT` class provides automatic failover between multiple STT providers for improved reliability. When one provider fails after exhausting its retries, it automatically switches to the next provider in the list.

## Features

*   **Automatic failover**: Seamlessly switches between providers when failures occur
*   **Audio buffering**: Retains audio chunks during failures and replays them to the next provider
*   **Circular rotation**: Cycles through providers indefinitely until transcription succeeds
*   **Zero configuration**: Works with any STT implementation

## Usage

```
import { FallbackSTT } from '@micdrop/server'import { OpenaiSTT } from '@micdrop/openai'import { GladiaSTT } from '@micdrop/gladia'
// Create a fallback STT with multiple providersconst stt = new FallbackSTT({  factories: [    // Primary provider: OpenAI with low retry count    () =>      new OpenaiSTT({        apiKey: process.env.OPENAI_API_KEY || '',        maxRetry: 2, // Fail faster to switch to backup      }),    // Backup provider: Gladia    () =>      new GladiaSTT({        apiKey: process.env.GLADIA_API_KEY || '',        maxRetry: 3,      }),  ],})
// Use with MicdropServerconst server = new MicdropServer(socket, {  stt,  // ... other options})
```

## Options

Option

Type

Description

`factories`

`Array<() => STT>`

Array of factory functions that create STT instances

## How It Works

1.  **Initialization**: Starts with the first provider in the list
2.  **Normal operation**: Forwards all audio to the current provider and emits transcripts
3.  **On failure**: When a provider emits the `Failed` event:
    *   Destroys the current provider
    *   Moves to the next provider (wraps around to first if at end)
    *   Replays buffered audio chunks to the new provider
4.  **Logging**: Inherits logger configuration and applies it to child providers

[Previous← FallbackAgent](/docs/ai-integration/fallback-strategies/agent-fallback)[NextFallbackTTS →](/docs/ai-integration/fallback-strategies/tts-fallback)

On this page

*   [Features](#features)
*   [Usage](#usage)
*   [Options](#options)
*   [How It Works](#how-it-works)